peters



tait@ tatrs atrnt @fitta JOHN L. LAY, 'OF BUFFALO, NEWv YORK, ASSIGNOR TO HIMSELF AND H, O. PERRY, OF 'SAME PLACE.

Lettera Patent No. 66,972, dated July 23, 18.67.

IMPROVEMENT IN STEAM ENGINES.

TO ALL WHOM IT MAY CONCERN:

Beit knownthat I, JOHN L. LAY, of the city ofBnffalo, in the county of Erie, and State of New York, have invented certain new and useful Improvements in Marine Steam -Engines; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawing asa part of this specification, which represents 4a vertical section of my improved engine.

My invention relates to that class of vertical compound engines in which the exhaust stearnvfrom the smaller cylinder is led directly to and acts upon the piston of the larger cylinder. It consists in the arrangement hereinafter described for actuating the two pistons, and in the use of a man-hole in the piston, in the bottom head, and the head intermediate the two cylinders.

In the drawings, A represents the upper and usually smaller cylinder, and B the. lower cylinder, arranged vertically one above the other, with their axes coinciding, and which may be cast together, with a single plate or diaphragm, C, forming the bottom head of the upper and top head of the lower cylinder. The piston D of the upper cylinder is attached to the lower end of. a rod, E,Iwhich passes upward through the cylinder-head, where it is fastened to the centre of a cross-head, F. At each end of this cross-head are secured similar rods Gr G, which descend through suitable guides h, attached to arms it', projecting from the cylinder, and thence through the top head C into the lower cylinder, where they are secured to the piston K, as represented. The working rod L is attached at its upper end to the centre of piston K, and passes thence ldownward through the bottom head M of thelower cylinder. Man-holes N O P are respectively formed in the Aintermediate head C, piston K, and bottom head M, as shown', for purposes presently to be explained. Figure 2 represents a modification of the above-described mode of operating the pistons, in which the rods G pass outside of the lower cylinder, and are secured to a cross-head, Q, beneath, similar to F, with asingle rod, L, or two rods, for operating the lower piston, as may be preferred..- The use of the man-hole P enables ready access .to be had into the lower-cylinder, and the man-hole O furnishes a passage to t'he top of the piston when it is required to be inspected, readjusted, or any of its rings removed or exchanged, which, by their employment, iseasily accomplished. Where entrance into the cylinder is effected from the top the man-hole O permits access to the bottom of same with equal facility without removing the opposite head. The man-hole N is designed to furnish a passage through which a person in the lower cylinder can inspect the upper without requiring its top head to be removed or the separation of any of the working parts of the engine. The man-holes may be made of any suitable construction. By my improved mode of actuating the pistons the employment of a stalling-box in the intermediate head C is avoided. This is a matter of considerable importance, owing to the difliculty of access to a box formed between the two cylinders, inasmuch-as ingress must rst be had into one of them before the packing can be examined. The guides hin the arms z' steady the rods F G in their movements. and prevent that vibration which would otherwise occasion great wear in the stuiing-boxes s t t. y

The-object and advantages of this method of connecting the pistons D K are to especially adapt the engine to vessels driven by a screw, it being important so to arrange the machinery as to have its greatest weight as low as possible in the vessel and admit of connecting with the screw-shaft. By connecting both pistons together and driving directly below the centre thereof, I secure a more compact arrangement, both of the weight and power, than has heretofore been obtained, adapted particularly to'vessels intended for navigating shallow waters.

What I claim as my invention, is

The combination with the abutting vertical `cylinders A B, with the piston-rods E G G L, and cross-head or heads F, arranged and operating substantially in the manner and for the purpose set forth.

I- also claim forming a man-hole in the piston K, substantially as and for the purpose specified.

I also claim the arrangement ofthe man-hole I in the bottom head of the lower cylinder with the man-hole O, substantially in the manner and for the purpose described.

i I also claim the man-hole N in the intermediate head of the vertical .abutting cylinders A B, arranged .with reference to the man-hole O in the piston-head, substantially as and for the purpose set forth.

I also claim the guide-arms z'z', in combination with the rods Gr G and cylinders A B, operating substantially as and for the purpose specified.

JOHN L. LAY.

Witnesses:

JAY HYATT, J. R. Darum. 

